1. Field of the Invention
The invention relates to a low temperature starting system for internal combustion engines, comprising: cylinders within which a fuel may be burnt and which produces combustion gases; pistons, each of which is housed in one of said cylinders; a crankshaft coupled to said pistons; a flywheel mounted to said crankshaft; a ring gear attached to and coaxial with said flywheel; an air inlet manifold; inlet valves associating said inlet manifold with each of said cylinders; an exhaust manifold for said combustion gases; exhaust valves associating said exhaust manifold with each of said cylinders; a turbocharger feeding said inlet manifold and which is driven by said combustion gases; a cooling radiator adapted to be inserted in said inlet manifold; an air starter motor adapted to drive said ring gear; means for supplying air to said air starter motor for actuation thereof; a fuel pump adapted to attain different frequency rates; and means for reading the speed of rotation of said crankshaft.
2. Prior Art
In Spanish patent no. 464.585 and the corresponding U.S. Pat. No. 4,232,521, the present applicant disclosed a process and a system for starting internal combustion engines. This process and system solve the problem of starting a supercharged engine, by overcoming the inoperativeness of the turbo blower supercharging the engine by applying a sufficient precompression to achieve starting without difficulty. This precompression is achieved by injecting compressed air from the outside and the injection is effected by the inclusion of an independent turbo blower unit, the outlet of which is connected to the engine inlet manifold.
The system referred to above, nevertheless, is of reduced efficiency for starting engines subjected to glacial temperatures, whereby there is evidenced the interest that exists in being able to provide all engines that have to operate under adverse weather conditions with the necessary conditions for a reliable start up.
For all vehicles parked outside or under scarcely protected covers in Arctic or continental areas subject to sharp temperature drops there is the risk of it being impossible to start the diesel engine after one of such drops.
The most important open cast mine workings, as well as the largest road haulers, have warning winkers installed at the regular motor vehicle parking lots, to advise of the need not to switch the engines off when the weather forecast so advises.
This means that, at certain heights or latitudes, the engines are left running, or ticking over for most of the time (i.e., an engine running at low speed ), for months on end (sometimes all winter).
This no-load running not only means a significant fuel consumption but also, because of the sulphur content of the present Diesel fuels, when the engine is ticking over (engine running at a low speed) at a relatively low temperature, causes the combustion products to condense in fine droplets of dilute sulphuric acid causing rapid wear of the cylinders, rings and pistons, dramatically shortening the working life of engines subjected to such conditions.
Furthermore, a vehicle with its engine running all night long may be highly polluting for the environment, both because of the fumes and because of the noise, in the case of vehicles parked near motels or residential areas.
It frequently happens that, to avoid such pernicious effects, an attempt is made to avoid extended no-load running as much as possible, which means that the user tends to refrain from connecting the alarm signal within the limits deemed to be prudent.
Nevertheless, in continental climates, sharp temperature drops are common and these, in the best of cases, may cause urgent mobilization of the personnel in the early hours of the morning to set the engines of a fleet running and, in the worst of cases, it may mean complete or partial blockage of a fleet for hours or even days.
In view of this situation, is is an aim of the invention to provide a system which allows an engine to be stopped as long as possible, while ensuring the immediate availability thereof at all times.